The invention relates generally to electrical components for power conversion, and more particularly, to integrated inductor and capacitor components.
Efforts are ongoing to increase power density for electrical switching power converters. Many switching power converters employ controllable switches in conjunction with capacitive and inductive energy storage elements to convert power from one voltage or current to another in a controlled and efficient manner. As will be recognized by one skilled in the art, capacitive energy storage refers to the storage of electrical energy in an electric field, and inductive energy storage refers to the storage of electrical energy in a magnetic field. Typically, the capacitive and inductive energy storage tasks are performed separately by capacitors and inductors. However, it has been proposed that a single element (an integrated LC component) can integrate both types of energy storage, with the purpose of increasing the power density of power converter circuits. At present, most integrated LC components for use in power converters suffer relatively high losses and hence have not yet achieved practicality.
In most implementations, the integrated LC component has an element that is formed by having two long conductors separated by a dielectric, which forms a capacitor. This pair of conductors may then be formed into a coil, which enhances its ability to function as an inductor. Thus, both capacitive and inductive energy storage occupy the same volume.
One disadvantage of the typical integrated LC component implementation is that the area of the two conductors is constant along their length, but current density is not. This may result in increased losses and larger components than necessary. Another disadvantage is that the typical implementation of the conductors is that of a solid copper plane. This can result in high eddy current losses when the operating frequency is high.
It would therefore be desirable to provide an integrated LC component with a more uniform current distribution and thus lower losses.